GB883768A - Utilization of proton recoil energy in neutron irradiated vapour phase organic reactions - Google Patents

Abstract

<FORM:0883768/IV (b)/1> The conversion of organic compounds in the vapour phase is effected by passing the vapours through a reaction zone containing fibres or strips of hydrogen-yielding material which have at least one dimension not greater than 20 microns and which on bombardment with fast neutrons yield recoil protons and irradiating the zone with fast neutrons having an average energy above 100 e.v.; energy is imparted to the reactants by recoil protons from the fibrous material. The conversion is preferably effected inside a nuclear reactor which may contain fixed fuel elements 2, preferably solid though they may be liquid or gaseous, cooled by a liquid coolant entering through pipe 3 and leaving by pipe 4 or may be of the type in which the fissile material is suspended or dissolved in the coolant, e.g. liquid bismuth or water containing dissolved uranium or systems based on molten fluorides. Uranium 235 and 233 and plutonium 239 may be used as the fissible material as the element or as compounds or alloys and may incorporate elements of the same atomic number and moderators such as carbon, beryllium or ordinary or heavy water. Liquid sodium is the preferred coolant, and heat is extracted in an external heat exchanger, water, biphenyl, terphenyl or fused salts may also be used. Conversion zone 5 is filled with fibres having a diameter of 0.5-20 microns and made of organic polymers such as polyethylene of molecular weight 10,000-200,000, nylon, polyisobutylene or polystyrene which may be cross-linked or of inorganic hydrides such as lithium-7 hydride. The fibres have a true density of 0.5-2 gm/cc., a hydrogen nuclei to other nuclei ratio greater than 0.9 and occupy 1%-80% of the volume of the conversion zone so that the average density is 0.005-1.6 gm/cc. The conversion zone 5 acts as a moderator and, maintaining a flux of 109 to 1016 neutrons per cm2/sec., may contain an average 1020-1023 nuclei per cc. The material for conversion enters by pipe 6 and leaves by pipe 7. Conversions referred to are isomerisation of paraffins, alkylation of paraffins with olefins, hydrogenation, cracking and polymerisation such as the conversion of cetane to lubricating oil at 100 DEG F.-900 DEG F. and 1-1,000 p.s.i. which latter reaction is exemplified.